After occurrence of some disturbances in power system that causes the sever imbalance between generation power and electrical load, the power system frequency begins to decrease. To prevent power system frequency instability and stop the frequency decay below the power system allowable frequency limitation, load shedding schemes should be utilized by applying under frequency load shedding relay...

In recent years several catastrophic power systems blackouts have occurred worldwide. Various reasons have been declared for these failures. Economical limitations due to power system restructuring restrictions, inadvertent operation of protective relays and inefficient design of conventional load shedding schemes are of the most important reasons causing these blackouts. In fact, due to both e...

this paper presents a new centralized adaptive method under frequency load shedding. sometimes, after initial frequency drop following severe disturbances, although the system frequency returns to its permissible value, however, the system might become unstable due to voltage problems. in this regard, the paper proposes a new centralized adaptive load shedding method to enhance the voltage stab...

This paper presents a new centralized adaptive method under frequency load shedding. Sometimes, after initial frequency drop following severe disturbances, although the system frequency returns to its permissible value, however, the system might become unstable due to voltage problems. In this regard, the paper proposes a new centralized adaptive load shedding method to enhance the voltage stab...

power system blackouts have become a serious problem for electric utilities especially in recent years. different forms of system instability have emerged in recent blackouts, such as voltage instability and frequency instability. to counteract each form of system instability, special algorithms have been designed in the protection system, e.g. under frequency load shedding (ufls) and under vol...

when a distribution network consisting of distributed generations (dgs) is disconnected from upstream network, the system may be exposed to severe power imbalance. in order to prevent the damage of power plants, frequency relays operate and remove dgs from the network. in contrast to traditional methods, the main objective in new methods is to keep dg units in service in the islanded distributi...

Power system blackouts have become a serious problem for electric utilities especially in recent years. Different forms of system instability have emerged in recent blackouts, such as voltage instability and frequency instability. To counteract each form of system instability, special algorithms have been designed in the protection system, e.g. Under Frequency Load Shedding (UFLS) and Under Vol...